4x^2+18x=-8

Solution for 4x^2+18x=-8 equation:

4x^2+18x=-8

We move all terms to the left:

4x^2+18x-(-8)=0

We add all the numbers together, and all the variables

4x^2+18x+8=0

a = 4; b = 18; c = +8;
Δ = b2-4ac
Δ = 182-4·4·8
Δ = 196
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{196}=14$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(18)-14}{2*4}=\frac{-32}{8}
=-4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(18)+14}{2*4}=\frac{-4}{8}
=-1/2
$